Ya, the reports can be confusing and some of them don't take into account the part-timers, training, and some even include resident salary! I've also seen reports that don't take into consideration incentives and only report base salary. On my 2006-2007 US tour, I have been asking every program I visit about the offers their senior residents get and take (all have been PM&S-36). I have seen starting salaries anywhere from 60K to 150K but this can be deceiving.
Multi-specialty and ortho groups seem to offer bigger starting salaries with fewer salary incentives. They can do this because they usually have a large cash flow. However, if you start at 120K, you may receive small bonuses and cash incentives but you probably aren't going to make a whole lot over that your first year out. Docs in these groups seem to top out anywhere from high 100's to mid 200's.
Private practice groups usually offer you a lower starting salary with larger incentives. I believe this is because, in general, they have less cash flow and you are a greater risk to them (especially the smaller practices). However, the more revenue you produce, the bigger your bonuses are. A friend of mine in Florida was hired on at a base of 60K but with huge production incentives and is on track to make well over 100K his first year out. Another guy I know started with a small practice in Michigan at a base of 80K. However, he worked his butt off and made nearly 200k his first year out. As far as topping out goes, the sky is the limit (increase patient load, new locations, more docs, etc).
As I said, I've been talking to various residents at various programs and this seemed to be the case. There are also those crazy guys that graduate from residency and start their own practice from scratch. Obviously they will have lower salaries their first few years out as they are building a patient base (which many salary reports don't take into consideration either). We posted a JAPMA salary survey that seemed pretty darn accurate. It is somewhere on this forum so find it and take a look at it. Hope this helps.
I think the bottom line is that, as long as you are competent, hard working, and get good training, you will do well. I'm sorry to say that there are some in the profession that are none of the above!